Composition of matter comprising a sulfur dioxide containing solution of a polyamide



United Sttes Patent COMPOSITIUN F MATTER CGMIPRISING A SUL- FUR DIOXIDE CONTAINING SOLUTION OF A POLYAMIDE Norman Blake, Chaddsford, Pa., and William Spencer Shore, Grand Haven, Mich., assignors to E. I. du Pont de Nemonrs and Company, Wilmington, DeL, a corporation of Delaware No Drawing. Application March 22, 1956 Serial No. 578,079

11 Claims. (Cl. zen-30.8

wherein -Y-, representing 50 molar percentage of the final polymers is a member of the class consisting of i l and mixtures thereof with up to 25 mol percent of wherein R is a member of the class consisting of aliphatic and alicyclic hydrocarbons having at least two carbons with each amine group attached to a different carbon atom and wherein n is a large number, R is a member of the class consisting of hydrogen and lower alkyl, and A- is a member of the class consisting of wherein R"- is any hydrocarbon containing at least 2 carbon atoms, each carbonyl being attached to a different carbon atom, -Z being an aliphatic hydrocarbon radical containing 2 or more carbon atoms, each oxy bond being to different carbon atoms, with the proviso that where -A is C RIII C then at least one R is lower alkyl, the liquid of the said solution being from the class consisting of liquid sulfur dioxide and a mixture of a liquid, containing sufficient sulfur dioxide to be substantially saturated with sulfur dioxide at room temperature and atmospheric pressure, having the formula wherein R' is a saturated lower aliphatic compound containing no morethan two carbon atoms, X is at least ice one halogen from the class consisting of Cl, Br and F and m is a whole number from 1 to 6.

The above solutions are useful in the preparation of shaped objects by extrusion, casting and the like, for instance as exemplified hereinafter.

The following examples are cited to illustrate the invention. They are not intended to limit it in any manner. Parts are by weight unless otherwise noted. Inherent viscosity values are measured in meta cresol at 25 C. Methods for producing the polymers employed herein as well as other members of the class of defined polymers are described in United States Patents Nos. 2,731,445, 2,731,446 and United States application Ser. No. 555,761, filed December 28, 1955.

Example I Sulfur dioxide is liquefied by passing it into a pressure vessel cooled below its boiling point (10 C.). To 6 parts of liquefied sulfur dioxide, 1 part of the polyamide from dimethylpiperazine and terephthaloyl chloride having an inherent viscosity of 2.02 is added, and the pressure vessel sealed and warmed to room temperature. The vessel is rolled for two hours to assure complete dissolution of the polymer. At the end of this time the contents of the vessel are released through a fine orifice into the air. Fibers of this dimethylpiperazine polymer are produced. The inherent viscosity of the spun polymer is 1.86, indicating good molecular stability.

Example II 10 parts of chloroform are saturated with sulfur dioxide at 10 C. 1 part of the polyamide from dimethylpiperazine and terephthaloyl chloride having an inherent viscosity of 3.14 is found to be soluble in this solvent mixture whereas chloroform alone does not dissolve even a small amount.

Example III 79 parts of sulfur dioxide are liquefied as described in Example I and 21 parts of the polyurethane from piperazine and ethylene bis-chloroformate having an inherent viscosity of 2.24 are dissolved therein. A clear, tough, pliable, s'elf-sustaining'film of the polymeris cast.

Example IV A mixture of 50 parts of sulfur dioxide and 50 parts of dichlorofluoromethane (boiling point about 9 C.) is cooled in a pressure vessel to liquefy the gas mixture and 15 parts of the polyamide prepared from dimethylpiperazine and terephthaloyl chloride and having an inherent viscosity of 3.14 are found to dissolve therein. A tough pliable film is cast and filaments are spun from a rod dipped into this solution at room temperature.

Example V Example VI A mixture of about 40 parts of sulfur dioxide and 40 parts of ethylchloride (boiling point of about 12 C.) is cooled to liquefy the mixture and 21 parts of the polyurethane from piperazine and ethylene bis-chloroformate having an inherent viscosity of 2.24, are dissolved therein to form a clear solution. Tough pliable films are cast from this solution.

3 Example VII A mixture of about 45 parts of sulfur dioxide and 45 parts of methyl chloride (boiling point of about 24 C.) is cooled to liquefy the mixture and 10 parts of the polyurethane from piperazine and bis-chloroformate of propane 2,2'-dimethyl 1,3 diol having an inherent vis cosity of 1.67, are found to be soluble therein. The solu tion coats base sheet material such as paper, wood, cloth and the like, giving lustrous, smooth and adherent surfacings.

Example VIII A number of solvent mixtures are prepared from chloroform, methylene chloride, bromochloromethane and trichloroethane by saturating at room temperature each of these liquid halogenated hydrocarbons with sulfur dioxide gas or by saturating at room temperature the liquid halogenated hydrocarbon with a gas mixture of sulfur dioxide and a gaseous halogenated hydrocarbon as shown in the following list:

Sulfur dioxide/chloroform Sulfur dioxide/methylene chloride Sulfur dioxide/bromochloromethane Sulfur dioxide/trichloroethane Sulfur dioxide/ dichloroflu oromethane/ chloroform Sulfur dioxide/methyl chloride/chloroform Sulfur dioxide/ ethyl chloride/ chloroform Sulfur dioxide/dichlorodifiuoromethane/chloroform Sulfur dioxide/dichlorofluoromethane/methylene chloride Sulfur dioxide/ ethyl chloride/methylene chloride Sulfur dioxide/dichlorodifluoromethane/methylene chloride Sulfur dioxide/dichlorofiuoromethane/trichloroethane Sulfur dioxide/methyl chloride/trichloroethane Sulfur dioxide/dichlouoditluoromethane/trichloroethane Sulfur dioxide/ dichlorofluoromethane/bromochloromethane Sulfur dioxide/methyl chloride/bromochloromethane Sulfur dioxide/dichlorodifiuoromethane/bromochloromethane Each of these mixtures dissolves at room temperature to the extent of at least 10% each of the following fiberforming polymers and copolymers: (1) polyamide from dimethylpiperazine and terephthalic acid, (2) polyamide from dimethylpiperazine and isophthalic acid, (3) from dimethylpiperazine and 4,4'-bibenzoic acid, (4-) polyarnide" from dimethylpiperazine and hexahydroterephthalic acid, (5) polyamide from tetramethylpiperazine and terephthalic acid,- (6) polyamide from methylpiperazine and phthalic acid, (7) polyamide from methylpiperazine and terephthalic/isophthalic acids (0.8/0.2), (8) polyurethane from piperazine and ethylene bischloroformate, (9) polyurethane from piperazine and hexamethylene bis-chloroformate, (l0) polyurethane from dimethylpiperazine and the bis-chloroformate of propane 2,2-dimethyl 1,3 diol, (l1) copolymer from dimethylpiperazine and terephthalic acid and ethylene bis-chloroforrnate (l.0:0.75/O.25), (l2) copolymer from dimethylpiperazine/bis(4 aminocyclohexyl) methane and isophthalic acid (0.75/O.25:1.0), (l3) copolymer from dimethylpiperaZine/bis(4-aminocyclohexyl)methane and phthalic acid and isophthalic acid (0.75/0.25:0.6/ 0.4).

The high volatility of the solvent mixtures permits room temperature spinning, casting or coating of the solutions of this invention. Furthermore, at elevated temperatures such as 25 to 100 C. even higher concentrations of polymer may be dissolved. The solutions of this invention may be extruded through fine orifices by either the dry or wet spinning process to produce filaments and yarns or may be processed to form self-sustaining film or coatings on many types of surfaces.

As pointed out above, liquefied sulfur dioxide alone is useful as a solvent for the polymers defined within the present invention. Mixtures containing from as low as about 5% up to about sulfur dioxide and one or more of such halogenated derivatives of methane and ethane as dichlorofluoromethane, chlorodifluoromethane, dichlorodifluoromethane, methyl chloride, methyl fluoride, ethyl chloride, ethylene difluoride, chlorotrifluoroethane, chloroform, methylene chloride, methylene fluoride, bromochloromethane, trichloroethane, fluoroform, trichlorofluoromethane, chlorotrifiuoromethane, carbon tetrafluoride and carbon tetrachloride are also suitable. It is preferred that sufficient sulfur dioxide be present to permit the mixture to be saturated with sulfur dioxide \CH('IH R R and mixtures thereof with up to 25 mol percent of wherein R" is a member of the class consisting of aliphatic and alicyclic hydrocarbons having at least two carbons with each amine group attached to a different carbon atom and wherein -R is a member of the class consisting of hydrogen and lower alkyl, and -A is a member of the class consisting of II Ii OR-C and O H II -c-oz o-owherein R' is any hydrocarbon containing at least 2. carbon atoms, each carbonyl being attached to a different carbon atom, -Z being an aliphatic hydrocarbon radical containing 2 or more carbon atoms, each oxy bond being to different carbon atoms, with the proviso that where A is then at least one -R is lower alkyl, the liquid of the [said solution being selected from the class consisting of sulfur dioxide under pressure and a mixture of a liquid containing sufficient sulfur dioxide to be substantially saturated with sulfur dioxide at room temperature and atmospheric pressure, having the formula wherein R' is lower alkyl containing no more than 2 carbon atoms, X is at least one halogen from the class consisting of -Cl, Br, and -F and m is a Whole number from 1 to 6.

2. A composition of matter comprising a solution as defined in claim 1, wherein the liquid of the said solution is liquid sulfur dioxide.

3. A composition of matter comprising a solution as defined in claim ,1, wherein the liquid of the said solu- 1011 comprises a halogen substituted liquid as defined in claim 1 substantially saturated with sulfur dioxide at 9. A composition of matter as defined in claim 8 room temperature and atmospheric pressure. wherein the polymer is polydimethylpiperazinetereph- 4. The composition of claim 2 wherein the polymer thalamide. is polydimethylpiperazineterephthalamide. =10. A composition of matter as defined in claim 3 5. The composition of claim 2 wherein the polymer 5 wherein the halogen substituted liquid is ethylchloride. is polyethylene-l,4-piperazinedicarboxylate. 11. A composition of matter as defined in claim 10 6. A composition of matter as defined in claim 3 wherein the polymer is polyethylene-1,4-piperazinedicarwherein the halogen substituted liquid is chloroform. boxylate.

7. A composition of matter as defined in claim 6 wherein the polymer is polydimethylpiperazinetereph- 10 References Cited in the file of this Patent thalamide- UNITED STATES PATENTS 8. A composition of matter as defined in claim 3 wherein the halogen substituted liquid is dichlorofluoromethane.

2,731,445 Wittbecker Jan. 17, 1956 UNITED STATES PATENT OFFICE Certificate of Correction Patent No. 2,919,257 December 29, 1959 Norman Blake et a1.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Letters Patentshould read as corrected below.

Column 1, lines 38 to 40, the formula should appear as shown below instead of as in the patent:

E H (sen rt-) 001mm: 3, line 47, after (3) insert po1yamide.

Signed and sealed this 21st day of June 1960.

\snAL] muse:

KARL H. LAXLINE, ROBERT C. WATSON, Attestz'ng Qfiicer. Oomz'asioner of Patents, 

1. A COMPOSITION OF MATTER COMPRISING A SOLUTION OF A HIGH MOLECULAR WEIGHT POLYMER HAVING THE RECURRING UNIT 